The specific aim of this project is to study the details of the solution structure and electronic charge distribution of K13Ln(W11O39si)2 and K17Ln(P2W17O61)2 families of compounds using spectroscopic and computational techniques as well as X-ray crystallography. 1. Investigate the binding and detailed molecular interactions of the oxoanions with the gp-120 glycoprotein, or peptide sequences, representative of regions of the gp- 120 glycoprotein, using fluorescence techniques and NMR spectroscopy. We will correlate the binding of the oxoanions and the protein with the anti-HIV results obtained from our preliminary studies. 2. Using information derived above, design and prepare new families of polyoxoanions, which should provide more precise interactions with the gp- 120 glycoprotein.